If you are found to be eligible to take part in this study, you will be randomly assigned (as in the roll of dice) to one of 3 treatment groups (Group 1, Group 2, or Group 3). Participants in Groups 1 and 2 will receive treatment with ambisome. Participants in Group 3 will receive treatment with voriconazole. Participants in all 3 groups will begin treatment 24 hours after the last dose of chemotherapy.